Cinematograph-machine safety device



`lune 22 1926. 1,589,518

y A. L. DITTMER CINEMATOGRAPH MACHINE SAFETY DEVICE Filed Jan. l5, 1924 2 Sheets-Sheet l ll'g- 09- June 22 1926. 1,589,518

A. l.. DlTTMER CINEMATOGRAPH MACHINE SAFETY DEVICE Filed Jan. 15, 1924 2 sheets-sheet 2 Patented June 22, 1926.

UNITED STATES PATENT OFFICE.

CINEMATOGRAPH-MACHINE SAFETY DEVICE.

Application led `Tanuary 15, 1924, Serial No.

Cinematograph safety devices, for cutting off light rays from the film, do not so far as I am aware, cut ofi' the light when the film stops temporarily owing to worn or damaged sprocket holes in the film. These stoppages in some cases, allow the film to become ignited. The operator must give attention to preventsuch ignition as the cinematograph continues in motion when the film so stops, and vision only indicates the stoppage to the operator. I provide devices to cut the light off each time the film so stops, and when the film breaks, and also when the machine stops.

I provide a movable apertured plate, which is drawn into normal working position (as downwardly) by tensioned film passinlg between it and spring shoes on the film gate, which I hinge to the said plate and which plate is retracted (as upwardly) when the tension on the film ceases.

The downward movement of the apertured plate brings an apertured shutter into normal working position so that when the film is moving properly, during opera,-

tion of the cinematograph with the apertured plate lowered, the film is exposed to light rays which pass through a masking aperture in a rear plate. The shutter leaves the said normal working position upon return movement of the apertured plate, and thus intercepts the light rays.

I combine with my safety devices, if desired, a second shutter, which is well known, and which will in known manner be governed to close if the machine stops, or is sufficiently slowed, even though film tension be maintained. Inthe accompanying drawings I illustrate my invention as applied to a shutter of rotary type operated by movement of the apertured plate, but the details of the shutter and its movement maybe varied while still retaining features herein claimed.

In these drawings, Figure 1 is a front elevation showing my apertured plate and parte adajcent thereto.

Figure 2 is a plan of the parts in Figure 1.

Figure 3 is a side elevation of the parts in Figure 1.

Figure f1 shows my Amovable apertured plate in perspective view on a reduced scale.

Figure 5 is a detail view of the rotary 686,449, and in Australia November 27, 1923.

shutter, and attachments-the full lines showing the normal working position and dot and dash lines the safety position.

Figure 6 is a detail view of the block which receives the shutter control lever pin.

L shows one of the rays of the light which is projected through the film.

1 is a part of the machine casing, near which I support my apertured plate 2 which carries at each side a wing 3, set rearwardly therefrom by webs or distance pieces 3, Plate 2 has a hole 2al for the rays of light, all light mentioned herein being light projected towards the film to produce the picture, but the said light is intercepted for safety purposes when an emergency arises, as herein explained. Each wing is supported between upper and lower guide rollers, inner guide rollers being flanged and marked 4, 4, and outer guide. rollers 5, 5, near the respective sides of the machine. aXle projecting from brackets 6 and 7 respectively carried at each side on a shaft 8, each shaft being carried by brackets 9 so that it may be slidably adjusted longitudinally, and be secured in position` by set screvs 10; but the shafts are not rotatable, a groove 11 on each being engaged by bracket pins 12. 1

The brackets 6 and 7 have pins 13 engaging groove 11, and are resiliently held between spring washers 14.-, the tension on which is adjustable, by means of a nut. 15 on shaft 8. Each wing 3 has at 3b a flexible connection 16, which passes through a guide eye liand over a guide roller 1S, to .v

a controlled slidable stem 19, mounted in a bracket 2O fir-:ed to casing 1, the control means including a spiral spring 21, the pressure of which is at one end on nut Q2 onthe screw-threaded part of the stem, this nut being adjustable. A nut 23 is also adjustable on the latter part. of stem 19 to limit` during expansion of spring Q1, the stem movement during movement of the apertured plate 2.

I provide above and below the plate 2, buffers 24 having suitable resilience, the upper to prevent jar of the apertured plate, and the lower to limit movement of the plate when it changes its position.

Each guide roller is carried on an Upon one wing 3*(which has for the purpose holes 3) I provide a bracket 25, shown in Figure 2 (not visible in Figure 3) upon which is hinged a main apertured gate plate 26, which is of known construction, and which has at its upper part bearings-27 supporting an axle 2T carrying film guide rollers 28.

At the rear of plate 26 isthe rear ,apertured gate plate 3l having the hole 31a 'and connected by a stud 29 to plate E26, and having distance stops 30 as commonly used. Plate @Gis held in the closedv position shown by carrying a spring catch V32, which b ears against an abutment ping which projects through Va hole in fplate 26 and extends from a wing Plate 3l carries, at itsfront, springs'84'-`see Figures 2 and fz3-which exert pressure on Ilugs 35 which vextend from shoes 36. Y t.

4It is betweenshoes 36 and plate 2 that the film (partly shown and 'marked 37) is drawn during the'operation of the :cinematograph. 'I do not illustrate the parts numbered 25 to 36 `separately because they are known ldevices rIn the position in Figure 2, which I call the light transmitting position, there Varefive holes in register, namely, in order from the front, that of the apertured plate A2, main gate plate 2G, rear gate plate 31,'shutter 46 herein-after mentioned, andthe masking plate 38,"the said shutter and masking plate-not having hitherto been used las 'safety 'devices to prevent, or as means to regulate-light transmission. The shutter Vis rotatable, but the mraskingr plate will not be "moved during ordinary exhibitingandstoppa'ges oflin. Y Y

-Re'arwardly off late `-31 4is the -apertured masking plate "38 connected b'ylaf hinge y39 at one iside to 'a bracket l40, and held closed against a buffer 4l by a latch '42 on :plate 38 which engages a ybracket 48. -In plate 88 is "the light transmission 'aperture 44, which masks the picture, andjwhich is to the rearof the aperture 45,in the shutter 46, when the-latter is inthe illustrated position, in whichrays of light .pass through'it.

Shutter 46 is mounted'onl an axle 47 which projects 'from plate 38and will berotated or swung'over asuitable arc by means of a spring 48 r"as hereinafter explained. The spring lextends from a-lever Y49,*a'n'd engages a lug 50 on the shutteigmovementof which is limited byz'a 'stop 51, see Figure f5, located in thepath ofone 'orthe other of two-'shutterlugs52. Y Y

Stops" 57 f'on plate 38 arel provided to -limit movement of lever 49. A projection shown asa -pin '53 'extends 'from .lever 49' into a recess 54,se'eFigurefin abloc'k 55, whiclji is V'attached to .plate lVhen vertical moveme'nbof apertured -p'late'f-Qloccurs, itA Y'is transmitted .to "the blockg' and thus the pin; 53 :and the latter moves lever 49 Vwhich causes spring 48 to rotate shutter 46, both tion 53) it will readily re-enter the recess. Amrearinost shutter 58 is indicated in dotted lines in Figure 3, Ait bein-g usable at will. It can be operated in known manner by connections Vto a centrifugal governor.

in the operation ofthis improved cineinatograph, when the film 87 is moving in the ordinary manner (downwardly in the case illustrated) friction by the iii-m upon aportured plate 2 and shoes no draws these and their attached parts (including parts 3 and 25 toBG, block 55 having pin 53, and lever 49) 'dfnvnwardly, notwithstand-ing` the resistance 1of springs 21, into the position shown in the drawings. A

if the film breaks,or if its advance is arrested by reason of a worn or torn Vpari'zof the film meeting the gear which engages the film edges then the `tension on the film will cease, and apertured plate 2, and also the aforesaid parts thereto connected will be retracted (in this case upwardlv) by the springs 2l, thus causing shutter to locate its aperture 45 in about the position shown by dotted lines in Figure o, shutting oli' light through aperture 44, and therefore screening the light rays from the film, and producing safety conditions. itis sufficient to shut off the light by the movement of 1one aperture, so that the apertures in partsvl and 26, although they alter their position, do not necessarily get wholly out of the light transmitting position as their apertures in practice may be long or large.

l)What I claim is y l. In a cinematograph, a rotatable safety shutter combined with means which by 'friction of the film in motion are located so as to hold the shutter in a position which allows light to be projected throughthe shutterand lihn, the said frictionally positioned means containing an apertured plate connected to spring means, the plate being connected to'the shutter so that movement of the plate by the spring means causes the safety Ashutter tov turn on its axis to intercept the light and prevent the'latter striking theffllm. l

`21. In a cinematograph, a vsafety shutter A(.vombi'ned with means which by friction of the film in motion are located so as vto hold thejshutter in Ia -position'which allows the light togbe projected through 'the shutter and the film, the said frictionally,positioned means `"containing an aperturedplate connected to spring'means, 'the pla'te being connect'ed to the shutter so that movementof -the plate by -the spring -meansVV causes .the

llt)

.lll

3. In a cinematograph, a safety shutter combined with means which by friction of the film in motion are located so as to hold the shutter in a position which allows light to be projected through the shutter in the film, the said frictionally positioned means containing an apertured plate connected to spring means, the plate being connected to the shutter so that movement of the plate by spring means causes the safety shutter to intercept the light, and prevent the latter striking the film, and resiliently mounted rollers for guiding the apertured plate.

4f. In a cin-ematograph, a supporting plate having an aperture to permit the passage of lightrays to the film, a rotatable shutter mounted on said plate and having a window adapted to align with said aperture, said shutter being rotatable in a plane parallel to the plate, a reciprocating plate mounted forwardly of the shutter and having a window adapted to align with the window of the shutter during the normal operation of the machine7 resilient means normally i tending to move the reciprocating plate in one direction, friction means on the reciprocating plate adapted to engage the film for moving the reciprocating plate in the opposite direction, and means connecting the reciprocating plate to the shutter for causing turning of the shutter when the reciprocating plate is moved under the influence of said resilient means.

5. In a cinematograph as claimed in claim 4, guide rollers for causing the reciprocating plate to move in a rectilinear path.

6. In a cinematograph, a slidable apertured plate, a film gate hinged to it, a film masking plate rearward of the gate, and on the masking plate a safety shutter which is tercepting position and operative position I as required ya safety shutter carried on the masking plate.

8. The construction in claim 6 and with the slidable apertured plate and the film gate provided with means to locate in light intercepting position and in operative position, as required, a safety shutter carried on the film masking plate, a block on the rear of said plate, a recess in the block, a pin Aengaging the recess, the recess having a spring pawl to admit the said pin, when the latter becomes disengaged from the said recess.

9. In a cinematograph, a vertically slidable apertured plate having Wings, guide rollers engaging the wings, spring means tov draw the plate into safety position, stops to limit the plate movement, a film gate hinged to the plate, and carrying film directing rollers and friction shoes, a masking plate outwardly of the film gate, a rotary safety shutter inward of the masking plate, and means for transmitting movement from the apertured plate and film gate to set the F safety shutter.

10. In a cinematograph as claimed in claim 4, guide rollers for the reciprocating plate, and adjustable means supporting the guide rollers and movable in a direction perpendicular to the reciprocating plate.

h Ini Witness whereof I have hereunto set my ARTHUR LESLIE DITTMER. 

